Astrophytum asterias, as it is well known, is a spineless cactus, with a perfectly geometric form resembling that of the sea-urchin. The stem is globose, quite flattened and reaches a diameter of 10 cm and a height of 8 cm. It usually has eight flat ribs, separated by shallow furrows. The areoles are conspicuous, white, 3-4 mm wide, usually woolly. The colour of the plant is grayish-green, and the epidermis is covered by white dots arranged sometimes along lines, sometimes according to more irregular patterns. The flowers are about 5 cm wide and 3 cm long, yellow with a reddish throat. The fruit is green, initially spherical, but it elongates on ripening, becomes soft and detaches just above the base when pulled lightly. The seeds (with a very large hilum) are smooth, shaped like a cap, from black to brown in colour. The unique forms known as 'Super Kabuto' and 'Mirakuru Kabuto' are distinguished from the normal Astrophytum asterias by the epidermis, that does not have simple dots, but a mosaic of extensive white spots that make the plant look intensely maculate. In Japan there are many and beautiful forms of 'Super Kabuto', which differ for the diverse pattern of these spots. It would be difficult to mention them all: they range from completely white forms ('white-type'), to forms with woolly spots ('snow-type'), to forms with a maculation like the shape of fly's wings ('zebra-type').

Photo 1. A specimen of 'Super Kabuto zebra-type', grafted on Myrtillocactus geometrizans. Notice the white patterns in the shape of fly's wings.

The first specimens of Astrophytum asterias were collected by the baron W. von Karwinsky in the spring of 1843 in Tamaulipas, Mexico. Sent to Munich in Bavaria and described by Zuccarini in 1845, they died soon without leaving descendants. Very few were found between 1910 and 1920. In 1922 Britton and Rose, in the classic treatise "The Cactaceae" had to use, as an illustration, the photograph of one of the dried plants kept in Munich. Only after 1920 did the Haage nursery import some specimens to Europe, and from thereon diffusion among collectors began.

The story of the forms called 'Super Kabuto' and 'Mirakuru Kabuto' is hazier, though more recent: the information on the origins and cultivation of these plants is indeed scarce, sometimes discordant and absolutely non exhaustive. To make things worse, the little information available is often in Japanese, a language that for sure many people ignore. All this results in the fact that these plants are shrouded in mystery and legend.

What is the true origin of these particular Astrophytum? Do they all come from a natural hybrid? And still, what is the difference between 'Super Kabuto' and 'Mirakuru Kabuto'?

According to Tony Sato, the 'Mirakuru Kabuto' (the name, given by Sato himself, in Japanese means 'miracle' of Astrophytum asterias) would come from a mutation that occurred in nature to Astrophytum asterias. These mutated plants were imported to Japan by Mr. Masaomi Takeo in 1980. The first hybridization attempts with normal Astrophytum asterias produced a first generation that did not show the same characters of 'Mirakuru Kabuto'.

Clive Innes and Charles Glass (in their 'encyclopaedia', 1991) almost wholly confirm these facts, stating that Astrophytum asterias 'Mirakuru Kabuto' is "an extraordinary variant known from just one individual field-collected plant and sold at a high price in Japan. Propagations have been made possible by cross-pollinating with the typical form or by grafting. The title is Japanese for 'miracle plant'2.

This is the only information I have obtained on the origin of the 'Mirakuru Kabuto', and from which several questions arise. How did Mr. Masaomi Takeo successively manage to obtain plants with the characters of 'Mirakuru Kabuto'? And if he had success, in what proportion did these characters show in the descendants? And why is it that today the 'Super Kabuto' are mentioned more than the 'Mirakuru Kabuto'?

As regards the origin of the 'Super Kabuto' the information is even scantier!

Tony Sato states that the 'Mirakuru Kabuto' is distinguishable from the 'Super Kabuto'. The dots of the latter would be raised, while those of the former would not. To make it clearer, this difference could be similar to the better known one between Astrophytum coahuilense (with "woolly" and "raised" dots) and Astrophytum myriostigma (with flat dots on the plant's epidermis). Furthermore, the 'Mirakuru Kabuto' could grow up to 19 cm in height, while the 'Super Kabuto' would be smaller.

'Super Kabuto' is supposed to be a specimen of a mutated form of Astrophytum asterias found in 1981 by the same Mr. Masaomi Takeo in an American garden centre. But where does this plant come from? Is there a relation between 'Mirakuru Kabuto' and 'Super Kabuto'?

According to Mr. Yowichirow Matsuoka - an expert Japanese collector of Astrophytum - the 'Mirakuru Kabuto' and 'Super Kabuto' would have been imported from Mexico to Japan in 1979. Therefore they should be different mutations of Astrophytum asterias both generated in nature3.

Photo 5 a, b. Two A. asterias grafted on the same specimen of Pereskiopsis velutina, and a hybrid of 'Super Kabuto'.

Still according to Yowichirow Matsuoka, crossing a 'Super Kabuto' with an Astrophytum asterias intensely covered with white dots, the percentage of first generation plants with 'Super Kabuto' characters is about 50%4. These percentages seem to have been confirmed by other Japanese collectors5.

Instead it seems to be much more difficult to obtain the characters of the 'Mirakuru Kabuto' form from crosses with normal Astrophytum asterias. This may explain why today we hear a lot about 'Super Kabuto' and little about 'Mirakuru Kabuto'.

1 'Kabuto' is the Japanese name of Astrophytum asterias.
2 According to Aikichi Kobayashi (see references) the photograph in the Illustrated Encyclopaedia of Cacti should be a 'Super Kabuto' and not a 'Mirakuru Kabuto'.
3 According to some Japanese cactus experts, the site where the mutations were found is Calles, in Mexico.
4 Yowichirow Matsuoka found percentages even higher than 50%.
5 Contrary to these data, according to Robert Maijer and K. Sakai - Japanese nurseryman - the percentage of plants with 'Super Kabuto' characters obtained from crossing with a normal A. asterias is only about 30% in the first generation (F1).